documentation is constantly refined as detailed under­ 1.1 Purpose standing of the requirement increase. The CCT A of the UK government and Siemens For project management purposes the SSADM life Nixdorf (SNI) have undertaken a joint project to com­ cycle is defined in terms of work packages, modules, pare the CCTA's methodology SSADM and Siemens stages and steps. Each work package is completed when Nixdorf's product GRAPES]). SSADM is an analysis a specified set of documentation is produced and satis­ and design methodology for computer systems. fies specified quality criteria. All activities undertaken at GRAPES is a graphical language used within the each point are those necessary to produce the required framework provided by the DOMINO@: process tech­ documentation. nology of Siemens Nixdorf for analysis and design of information systems. (In the 1991 Statement of Direc­ The analysis is undertaken concentrating on three key tion it was declared the Siemens Nixdorf main line for perspectives: modelling technology.) The study was undertaken in February and March 1991. . functions (users' views of system processing to react to events) The goal of the study was to compare SSADM and . events (real-world business events, e.g. "receipt of DOMINO/GRAPES to discover whether both application", or system-generated, e.g. end-of-month approaches elicit the same knowledge about a system.